I find the best solution is to simply never use a social media account attached to your real identity.
Innocent comments taken out of context or a general changing of accepted speech can turn a decade old bit of text into damning evidence of bigotry, racism, or any other ism.
The problem with autodelete or timed content is with caching services. There are a number of sites that allow you to see deleted comments. If a social media service is large enough, I imagine the same will be created.
Once something is on the internet, it is always on the internet.
Innocent comments taken out of context or a general changing of accepted speech can turn a decade old bit of text into damning evidence of bigotry, racism, or any other ism.